The present invention relates to a head-mounted type image display apparatus.
One conventional image display apparatus typically comprises an image display unit held on the temple side of eyeglasses and an eyepiece optical unit held on the lens side of eyeglasses, whereby image-bearing light leaving the image display unit is entered into the viewer s eyeball through the eyepiece optical unit so that it can be viewed in the form of an image. Prior arts in this regard, for instance, include an arrangement having a hologram device located on the lens segments of eyeglasses (see JP(A) 2006-209144).
There is another eyeglasses type image display apparatus proposed in the art, which is held on the frame or the like of eyeglasses and positioned on the outside of lenses or which has an optical path through the lenses of eyeglasses. See U.S. Pat. Nos. 3,871,188 and 3,429,320, and JP(A) 2006-003879.